In a general liquid crystal display device, a drive circuit is provided outside an image display area where a large number of pixels are arrayed to form an image to be displayed. The drive circuit applies, to a scanning signal line connected to gates of thin film transistors (TFTs) formed corresponding to the pixels, signals for controlling on and off of the TFTs. For example, a prior art discloses a liquid crystal display device in which drive circuits formed of TFTs are disposed on both right and left sides of a display area (See Japanese unexamined published patent application No. 2012-32608).
In a liquid crystal display device, there is a demand to achieve higher resolution, which corresponds to increasing the number of pixels in the image display area, and to achieve a narrower frame, which corresponds to reducing the size of an area outside the image display area.
In view of this, in the case where the drive circuit for the scanning signal line is provided outside the display device as in the liquid crystal display device disclosed in the prior art, the drive circuit is difficult to downsize beyond a certain limit due to a restriction of materials forming the drive circuit. This becomes pronounced in the case where the materials forming the drive circuit are materials, such as amorphous silicon and the like, which have relatively small electron mobility. For this reason, there is a limit on achieving a narrowed frame in the configuration in which the drive circuit for the scanning signal line is provided outside the display device, and it is difficult to further decrease a frame width by existing techniques.
At the same time, in the case where the scanning signal lines are individually connected to an integrated circuit by using wiring made of a material, such as metal, which has a large electric conductivity, the number of scanning signal lines to be connected is considerably increased in order to achieve high resolution of an image display area, and an area where the wiring is disposed is enlarged. Therefore, it is still difficult to decrease the frame width by the existing techniques.